Recent Results of Helical Nonneutral Plasmas on Compact Helical System (CHS)

Journal Article · Wed Oct 18 04:00:00 EDT 2006 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2387907· OSTI ID:20891703

Himura, H; Yamamoto, Y; Sanpei, A; Masamune, S ^[1]; Wakabayashi, H; Isobe, M ^[2]

---

1. Kyoto Institute of Technology, Department of Electronics, Matsugasaki, Kyoto 606-8585 (Japan)
2. National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan)

First of all, non-constant space potential {phi}s and electron density ne on magnetic surfaces of helical nonneutral plasmas are verified experimentally. The difference in {phi}s enlarges significantly at the outer region inside the closed magnetic surfaces, and the corresponding equipotential surfaces are inferred to shift upward vertically with respect to magnetic surfaces. Meanwhile, larger value of ne is clearly observed in the downward region (z < 0) of magnetic surfaces, which seems to be consistent with the {phi}s measurement. These results are the first evidence which strongly suggests the equilibrium proposed for nonneutral plasmas confined in closed magnetic surfaces. Secondly, in order to investigate the mechanism of the multiple disruption of helical nonneutral plasmas observed in experiments, space and time evolutions of electron flux are measured carefully inside the magnetic surfaces, when the plasma disruption occurs. Surprisingly, a set of data show that the observed disruption is at first happened at {rho} {approx} 0.8, where {rho} is the normalized minor radius, and then, it seems to propagate inside magnetic surfaces.

• OSTI ID: 20891703
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 862; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ELECTRON DENSITY
ELECTRONS
EQUILIBRIUM
EVOLUTION
MAGNETIC SURFACES
PLASMA
PLASMA DENSITY
PLASMA DISRUPTION
PLASMA INSTABILITY
POTENTIALS